MarkerCluster.Default.css

.marker-cluster-small {
	background-color: rgba(255,255,255,1);
	}
.marker-cluster-small div {
	background-color: rgba(0, 200, 80, 1);
	}

.marker-cluster-medium {
	background-color: rgba(255, 255, 255, 1);
	}
.marker-cluster-medium div {
	background-color: rgba(255, 204, 0, 1);
	}

.marker-cluster-large {
	background-color: rgba(255, 255, 255, 1);
	}
.marker-cluster-large div {
	background-color: rgba(240, 120, 0, 1);
	}
.marker-cluster-extralarge {
	background-color: rgba(255,255,255,1);
}
.marker-cluster-extralarge div {
	background-color: rgba(240,50,0,1);
}	
.marker-cluster-xxlarge {
	background-color: rgba(255,255,255,1);
}
.marker-cluster-xxlarge div {
	background-color: rgba(90,0,20,1);
	color: #F00;
}		
	/* IE 6-8 fallback colors */
.leaflet-oldie .marker-cluster-small {
	background-color: rgb(181, 226, 140);
	}
.leaflet-oldie .marker-cluster-small div {
	background-color: rgb(110, 204, 57);
	}

.leaflet-oldie .marker-cluster-medium {
	background-color: rgb(241, 211, 87);
	}
.leaflet-oldie .marker-cluster-medium div {
	background-color: rgb(240, 194, 12);
	}

.leaflet-oldie .marker-cluster-large {
	background-color: rgb(253, 156, 115);
	}
.leaflet-oldie .marker-cluster-large div {
	background-color: rgb(241, 128, 23);
}

.marker-cluster {
	background-clip: padding-box;
	border-radius: 20px;
	}
.marker-cluster div {
	width: 30px;
	height: 30px;
	margin-left: 5px;
	margin-top: 5px;

	text-align: center;
	border-radius: 15px;
	font: 12px "Helvetica Neue", Arial, Helvetica, sans-serif;
	}
.marker-cluster span {
	line-height: 30px;
	}